Centrifugal air washer and conditioner



July 20, 1954 w. J. CALDWELL 2,684,232

CENTRIFUGAL AIR WASHER AND CONDITIONER Filed June 27, 1951 INVENTORQ WILLIAM J. CALDWELL '4 iz/WW ATTORNEY Patented July 20, 1954 CENTRIFUGAL AIR WASHER AND CONDITIONER William J. Caldwell, Independence, Mo.

Application June 27, 1951, Serial No. 233,752

1 Claim.

This invention relates to air washing and conditioning apparatus as employed in association with air conditioning systems.

It is an object of the invention to provide air washing and conditioning apparatus of relatively compact form which is able, within nominal limits, to dehumidify air passed therethrough and to deliver the air therefrom in a controlled amount of saturation at a desired dry bulb temperature.

Other objects of the invention provide air washing and conditioning apparatus in which the moisture content of the air introduced thereinto can be reduced beyond that which can be obtained by the spray water of a given temperature and to provide means for regulating the amount of expansion cooling which takes place.

The apparatus provided by this invention develops a tornado effect upon the air at the vortex of the washer, which tornado effects an expansion cooling upon the air stream, which causes a further reduction of the moisture content and a mechanical ejection of the moisture so released, so that the air leaving the device is in less than a saturated state.

Further objects and advantages of the invention, residing in the construction, arrangement and combination of parts will appear clear from a consideration of the following description of one practical form of the invention, by example with reference to the accompanying drawings, in which:

Fig. I is an elevation looking onto the inlet volute of this form of the invention,

Fig. II is a side view of Fig. I,

Fig. III is a plan View,

Fig. IV is a vertical section taken on an oblique plane, and

Figs. V and VI are schematic views of alternative surge relief valves.

Referring to the drawings, the centrifugal washer-conditioner is shown as comprising a casing structure including an inlet volute Ill, mounted on top of an inverted body [2, itself mounted upon a base structure, in the form of a shallow Water sump i l, in which the residual Water from the water sprays, injected at E6 into the air inflow through the volute I0, is collected.

Mounted within the body 12 in depending relation to the volute H1, is a cylindrical outlet duct 98, the upper end of which communicates with an outside extension 20 of this outlet duct, by which extension the air treated within the washer-conditioner is conducted away for use, as to a pressure vane blower of the system disclosed in my co-pending application, Serial No. 187,258, filed September 28, 1950. This outlet duct extension is shown dotted in position in Fig. III, as extending over the end portion, indicated generally at 22, of the inlet volute which opens into the annular space 24 defined within the coned body l2, between the upper end portion and the cylindrical outlet l8.

The inlet volute it has its entrance indicated Ill.

The outlet duct l8 carries a bottom cylinder extension 26, on the outside of which there is mounted a simple flared skirt or airfoiled section 28, either of which inclines outwardly and downwardly in such a manner as to reduce the air passage space between the discharge tube it and the sides of the cone [2. Provision is made both for adjusting the cylinder extension axially with respect to the outlet duct l5 (oi which this extension 26 forms a part) and of adjusting the flared skirt 28 axially with respect to its supporting duct H3.

The axial adjustment of the extension 28 has two major purposes, (1) to govern the suction pressure, and (2) to control the centrifugal elimination of moisture. Lowering the extension increases the suction pressure on the conical air passage around the duct l8 and thereby increases the centrifugal movement and thus increases the rotating speed of the air. This builds up the vortex of the cyclone, with an ensuing pressure drop therein. Greater expansion cooling results in that portion of the air actually entering the eye of the vortex of the cyclone. This action reduces the net dehumidifying of the air below that produced by the temperature of the spray water.

Extending upwardly from the water sump it into the bottom portion of the body i2, there is a cone 30. This is secured over the open top of the sump in such manner as not completely to fill the opening but to dominate the space beneath the central outlet duct [8 for the purpose of stabilizing the air flow by defining a specific physical path therefor.

In operation, air enters the washer. through the volute Iii, tangentially with respect to the central outlet duct I8 and enters the space 2 2 with a swirling, tornado-like motion, and on account of the outer tapered wall of this space and the resulting progressive decrease in the size of this space, causes the velocity of the air to be substantially increased.

Ignoring, for the moment, the presence of the flared skirt 28, when the air reaches the bottom portion of the coned body I2 it suffers a very abrupt reversal of direction in its passage vertically through the cental dischage duct I8, which abrupt change in direction causes a mechanical centrifugal ejection of entrained water from the air stream.

Returning now to the flared skirt, when the air stream in its rotative movement around the duct IS impinges upon this skirt, the air stream may (1) merely suffer a sudden restriction in the cross-sectional area of the passage 24, or (2) it may assume the form of a horizontal. doughnut shape tornado immediately beneath the skirt. Which effect occurs depends upon the position of the skirt 28 along the central discharge duct, as defined by the main duct cylinder l8 and its bottom extension 25-. It is in order to enable either effect to occur that the extension 26 is made axially adjustable with respect to the cylinder l8 and the flared skirt is made axially adjustable with respect to the extension. If the extension 26 is moved back into the cylinder M3, to shorten the efiective length of the cylinder, this simultaneously raises the flared skirt to cause the first condition above mentioned. With this condition, the sudden increase in velocity of the air causes any entrained moisture in the air stream to be effectively thrown out against the conical wall I2 to there by act as a free water eliminator without the need for employing the conventional eliminator plates and their attendant friction to air flow, which is objectionable.

As the flared skirt is lowered a critical point is reached, after which subsequent lowering creates the doughnut tornado efiect, above mentioned. This effect has been found to give rise to an extraordinary reaction,- equivalent to suddenly reducing the pressure of the center core of the spinhing doughnut of air through the centrifugal force of the spinning action, in the neighborhood of 17 inches (water gauge) and thus creatin expansion cooling within the doughnut of revolving air. Since the air stream is saturated at this point by virtue of its contact with the cold spray water at it, this sudden expansion causes substantial condensation to occur. This free water is thrown off by the violent circular motion involved and as the air is released from the tornado it assumes the normal pressure within the space where the air will have lost moisture beyond the saturation point of air at spray water temperature and is no longer saturated. Thus, even though the washer-conditioner will have actually dehumidifled the air it leaves the washer at less than saturation point.

In some instances, however, as in small size washers, the flared skirt need not be present. In such case, the aforesaid doughnut shaped tornado effect would be obtained by lowering the extension 23 to the point at which this effect occurs.

The purpose of the cone 3% is to assist in streamlining the upward air flow into the discharge duct it, as well as to stabilize the air activit as it assumes the tornado condition.

Since the water sump M is shallow in relation to the body l2 it is necessary to maintain close control over the water level therein to avoid overflowing. This is possible by the provision of a stand pipe 34 and fixed water level overflow pipe i s.

, The tendency of the air flow through the washer to assume a doughnut shape tornado encircling the lower end of the discharge duct is, 26, disturbs the even flow of the air through the washer, and gives rise to what is known as surging. Otherwise expressed, the air stream tends alternately to flip through the washer and chokeup, much as would happen in an air flow duct having a loose damper which alternately flipped across the duct, stopping the air flow, and then returned to allow normal free air flow to take place.

If this surging action were allowed to get out of control, the tornado effect would follow likewise, with the result that masses of static air would get pushed into the discharge duct, carrying entrained moisture along with it. It has been found that this surging action can be controlled by providing a simple trap door, or by-pass valve 33 hinged to the top of the inlet volute at to allow surge air to pass into the discharge duct connection. If provision is made to adjust this by-pass opening to suit the air volumes being handled, as by actuation of the adjusting screw ii in Fig. V, the tendency to choke up would be controlled, since the surge pulsations working bacl; against the inflow of air into the coned body would cause part of the inflow to be diverted through the by pass opening.

In Fig. VI there is shown a by-pa air flow range through the wash a figure the relief valve 33 is shown linked to a rocker arm 44 carrying an adjustable weight 46 and in turn connected to a dashpot 8.

The fixed bafile portion 59 seen in Figs. V erd VI provides a continuation of the top ll of th inlet volute iii, which pushes the passing stream downward and necessitates a reversal travel before air can pass outward into the d charge duct from within the coned body "1 ever a surge effect starts, which interrupts t smooth flow of air past the valve flap 58.

Having thus described my invention claim as novel and wish to secure by 1. Patent is as follows: I

A water spray washing and conditioning aoparatus characterized by the discharge of "'r less than saturation at the discharge temperature comprising a vertical casing structure definin an inverted frusto-conical wall, inlet volute conduit means at the top of said casing structure for the tangential admission of air into said casing st icture with a downward whirling action including water spray means for saturating the air entering said casing structure, a water sump in the bottom of said casing structure, a conical air deflector having its base disposed adjacent the bottom of said casing structure with an opening between said base and easing structure for the discharge of water into said sump, a discharge duct for the air depending centrally into said casing structure to define with the wall of said casing structure an air passage of progressively decreasing cross-section from the point of tangential dis charge of air into said casing structure to the lower depending end of said duct, the lower depending end of said duct defining with said conical air deflector and the lower portion of said casing structure an air discharge chamber is abruptly reversing the direction or air flow discharge through said discharge duct, at the point of maximum area restriction between said wall and said lower depending end of said discharge duct the air tangentially admitted to said. casing structure being induced by the increasing velocity and restriction into a tornado effect to produce a reduction in pressure and resulting expansion cooling at the core thereof due to cen trifugal action with resulting condensation of the otherwise saturated air, the cross-sectional area of said discharge chamber being greater than the cross-section area at the point of maximum restriction between said wall and the lower depending end of said discharge duct whereby air pressure is increased in said discharge chamber and the air flowing into said discharge duct is less than the saturation point, said duct carrying a cylindrical extension at its lower end, said extension being vertically adjustable with respect to said extension and said extension carrying an outwardly and downwardly flared skirt, said skirt being axially adjustable with respect to said extension.

References Cited in the file of this patent Number UNITED STATES PATENTS Name Date Bennett June 1, 1920 Stelz Jan. 19, 1932 Noyes Sept. 6, 1932 Bowen Mar. 27, 1934 Watson Mar. 23, 1937 Van Berkel Aug. 29, 1939 Dunham Sept. 8, 19 12 Crites Sept. 24, 1946 Hills May 18, 1948 Cox Aug. 28, 1951 

